1. Field of the Invention
The present invention relates to the field of display devices, and more particularly to a manufacturing method of a 3D display device and a grating device thereof.
2. Description of the Prior Art
The principle of present well-known 3D image display technologies adopts a binocular disparity for receiving different images from both left and right eyes of a viewer respectively, and finally the viewer's brain combines the images into a 3D image. In naked-eye 3D display technologies, there are three main types of structures, respectively: barrier, lenticular lens, and directional backlight, and the three structures have pros and cons. The lenticular lens is composed of a plurality of slender rectangular convex lenses arranged continuously along an optical axis, and the principle of light refraction is used for generating different left-eye and right-eye images, which are called a grating structure. Compared with the barrier structure that uses the light refraction to achieve the effect of dividing the light, the effect of less loss and higher brightness can be achieved. However, the refraction occurred at the edges of the lens structure is limited to result in a poor refraction, or the manufacturing discrepancy of the lenticular lens has a non-uniform lens surface to result in the production of stray lights and blurred 3D images and affect the overall 3D display effect. In addition, the barrier structure uses a whole row of barriers to limit the exit of light at a certain angle, such that the images at certain specific angles will be transmitted to the viewer's left and right eyes to generate the 3D image. Compared with the lenticular lens, the single-lens image is clearer, but the structural characteristics may reduce the overall brightness and resolution of the image.
As disclosed in R.O.C.(TW) Pat. No. M371902 entitled “Display device for switching 2D image/3D image display screen”, the display device includes a flat panel display and a parallax barrier panel installed on a display surface of the flat panel display, wherein the parallax barrier panel with a grid pattern includes a first electrochromic material layer and a second electrochromic material layer. At a 2D image display mode, the grid pattern, the first electrochromic material layer and the second electrochromic material layer are transparent; and at a 3D image display mode, the grid pattern is an opaque pattern, and the first electrochromic material layer has a first color, and the second electrochromic material layer has a second color. As disclosed in R.O.C.(TW) Pat. No. M368088 entitled “Integrated electrochromic 2D/3D display device”, a structure with a parallax barrier unit embedded into an LCD substrate comprises: a first substrate; a parallax barrier unit, disposed under the first substrate; a color filter unit, disposed under the parallax barrier unit; a common electrode, disposed under the color filter unit; a liquid crystal unit, disposed under the common electrode; a plurality of thin film transistors, disposed under the liquid crystal unit; a second substrate, disposed under the plurality of thin film transistors; and a light source, disposed under the second substrate; wherein the parallax barrier unit modulates the display of 2D images and 3D images and reduces the thickness and assembling cost of the conventional display device. Although the thickness of the LCD for displaying 3D images can be reduced since a transparent conductive layer and an electrochromic layer are disposed in a fence-shaped groove of an insulative transparent material, yet the actual manufacturing process of the grid patterned parallax barrier unit becomes relatively complicated.
In the aforementioned patents, an electrochromic material is used, and electrochromism (EC) refers to the phenomenon that light is absorbed or scattered by an electrochromic material under the effect of a current or an electric field to result in a reversible color change caused by redox reactions. However, the electrochromic devices of the aforementioned patents lack a necessary electrolyte layer required by electrochromic devices, since ions are not supplied to the electrolyte layer of the electrochromic layer, and the electrochromic device cannot produce a reversible oxidation or reduction to complete the change of coloration or decoloration or the coloration/decoloration speed is very slow. In addition, the transparent electrode layer and electrochromic material layer of the parallax barrier device are grid patterned, and whose manufacturing process requires a precise alignment for coating, spluttering or etching each laminated layer, and thus the manufacturing process is very complicated and the manufacturing efficiency is low.
Furthermore, the aforementioned patents adopt the conventional solid-state electrochromic material with the disadvantages of a low coloration/decoloration speed and a large driving voltage. For a quick speed and a small driving voltage, a liquid-state solution type electrochromic material should be used instead. However, the liquid-state solution type electrochromic material is not like the solid-state electrochromic material with a fence-shaped structure plated onto a conductive substrate surface, and thus it is necessary to form a barrier grating on the conductive substrate in order to fill the solution type electrochromic material. When the solution type electrochromic material changes its color, the blocked position is situated at a light transmitting status, and a manufacturing method of a 3D display device and a grating device thereof in accordance with the present invention can manufacture the barrier grating and package the solution type electrochromic material into the device within a primary manufacturing process, so as to simplify the manufacturing process and improve the manufacturing efficiency substantially.